h264: Remove MotionEstContext and move the relevant fields to H264Context

Unused buffers scratchpad and temp have been dropped too.
mpegvideo: move mpegvideo formats-related defines to mpegutils.h
mpegvideo: move ff_draw_horiz_band() to mpegutils.c

Drop the mpegvideo dependency for svq3 in configure.
mpegvideo: remove h264-only fields
h264 does not depend on mpegvideo any more
RGBA64 pixel formats

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
isom: fix C99-style declaration
codec_desc: update dvaudio tag
png: K&R formatting cosmetics
png: Support rgb48 and rgba64 encoding
raw, nut: Support rgba64 encoding
img2: add j2c file extension

Some applications use the j2c extension for jpeg2000 codestream files.
tiff: Support rgba encoding
fraps: set color_range
mjpeg: set color_range
mdec: set color_range
ljpeg: check color_range
libx264: check color_range
Merge commit '136034d86b5cb1819a2c3e6ecdfeb05dcba7140d'

* commit '136034d86b5cb1819a2c3e6ecdfeb05dcba7140d':
  h264: Remove MotionEstContext and move the relevant fields to H264Context

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'e0c16e4e3259cf50b5bac4c23bb6e517f397c74b'

* commit 'e0c16e4e3259cf50b5bac4c23bb6e517f397c74b':
  mpegvideo: move mpegvideo formats-related defines to mpegutils.h

Conflicts:
	libavcodec/h264_cabac.c
	libavcodec/h264_cavlc.c
	libavcodec/h264_mvpred.h
	libavcodec/svq1enc.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>